A function for enumerating front-door adjustment sets

[adam2392]

Is your feature request related to a problem? Please describe.
In causal estimation tasks, one is interested in typically using front door adjustment to estimate the total causal effects given a fully specified causal graph (i.e. nx.DiGraph, or pywhy_graphs.ADMG).

Describe the solution you'd like
Implement https://arxiv.org/pdf/2210.05816.pdf and refactor https://github.com/CausalAILab/FrontdoorAdjustmentSets to use the pywhy_graphs API.

Describe alternatives you've considered
Note that the algorithm does not work for Markov equivalence classes.